The Federal Aviation Administration (FAA) and other Air Navigation Service Providers (ANSPs) around the world maintain air traffic control systems (ATCs) to organize the flow of aircraft traffic in a particular airspace and to avoid conflicts and prevent collisions among airborne aircraft. To accomplish this task, ATCs rely on ground-based radar systems to determine the “state vector” of an aircraft which includes altitude, position, East-West velocity, North-South velocity, and vertical rate. Currently, ATCs use these state vectors to coordinate the flow of aircraft traffic, and ATCs maintain spacing between aircraft by dictating instructions to individual aircraft. However, individual aircraft do not receive the radar based state vector of other aircraft in the area, and aircraft rely on ATC to provide instructions that avoid conflicts and possible collisions with other aircraft.
ATCs are required to intervene and assign an aircraft a different speed, a level segment, or an off course vector if two aircraft are on flight paths that conflict. In some cases, ATCs will assign all three to maintain proper separation between aircraft. These interventions also add workload for the ATCs, increase fuel burn, cause excess carbon dioxide and nitric oxide emissions, and can increase noise levels experienced by the surrounding community.
In addition, pilots plan a phase of flight trajectories without knowledge of other aircraft in the area, and interventions by ATCs disrupt these plans. For example, when planning the descent phase of the flight, the pilot selects the desired descent speeds and determines the Top of Descent (TOD), which is the aircraft's transition between the en route phase and the descent phase of the flight. The pilot selects the desired descent speeds based on operational requirements such as maximizing fuel efficiency, improving the arrival time of the aircraft, or other parameters, such as turbulence avoidance, that characterize the flight trajectory. These operational requirements may be derived from a pilot flying the aircraft or the Airline Operations Control (AOC) that coordinates aircraft for an airline company. The operational limits used in determining the descent speeds can be set by the manufacturer, the aircraft operator, and the government regulators that oversee the operation of aircraft. On aircraft equipped with a Flight Management System (FMS) which automates certain in-flight tasks, the operational requirement may be set within the FMS to reduce cost or improve fuel efficiency. Prior to the TOD the pilot selects the appropriate speed profile within the FMS to plan a descent phase for the aircraft that, for example, minimizes fuel burn. In other instances, the operational requirement may be to fly faster and arrive at an airport to meet a scheduled arrival time. These operational requirements are inhibited and sometimes vitiated when an ATC intervenes during an aircraft's decent phase.
To supplement state vector information from ground-based radar systems, the aviation industry is developing and deploying the Automatic Dependent Surveillance-Broadcast (ADS-B) system, which requires an aircraft to broadcast state vector information determined by the aircraft's onboard sensors. The FFA defines the capabilities of ADS-B under the DO-260B standard. This change enables other aircraft in the area to receive the broadcasted ADS-B data and the state vector of other proximate aircraft. Now, aircraft are able to receive state vector information directly from other aircraft instead of solely relying on the ATC to provide instructions and avoid conflicts and possible collisions with other aircraft.
Even with knowledge of aircraft in the area, current trajectory generating devices are inflexible. These devices provide a pilot with either a single proposed trajectory that identifies the trajectory of minimum fuel burned or a single proposed trajectory that identifies the least amount of time required to fly the proposed trajectory. These trajectory solutions are limited to cruise flight that are accomplished by adjusting the speed, the vertical and/or the horizontal paths of the trajectory. When the devices provide single, automated solutions in this fashion, they remove the pilot and other entities from the decision making process and do not allow for more comprehensive, efficient solutions to be identified. While pilots can plan flight trajectories that best suit one operational requirement, pilots still rely on ATCs to ensure safe separation between aircraft.
In addition, pilots lack state vector information of surrounding aircraft, but pilots may also lack additional information including up-to-date wind information, special use airspace, turbulence information, volcanic ash reports, ANSP sector boundaries, letters of agreement between ANSP sectors, ATC sector loading, country over flight costs, temperature inversion layers, sonic boom regulations, the transport of wake vortices and sonic booms. Therefore, there is a need for a system and a method that generates a plurality of flight trajectories that synthesizes information from multiple sources and prevents or minimizes interventions by ATCs, which undermine the operational requirements associated with the aircraft.